Immortal Allen O'Neill
Attack on Huge HermitCollaboration Stages · Metal Slug Defense · 1/3
Energy30
Clear XP900
Base HP10,000
Map length4,500
Max enemies5
Spawn interval0.03s
Enemy traits 
Traitless
Traitless Crown difficulty
All enemies ×100% magnification
No restrictions
All enemies ×150% magnification
No restrictions
All enemies ×200% magnification
No restrictions
All enemies ×300% magnification
- Special · Rare only
Boss
Spawn timeline
Scroll sideways to see more. For enemies with a base HP condition, drag the orange circle to set when they appear.
Enemies 4 types
| Enemy | Count | Mag. | HP | Attack | First | Respawn |
|---|---|---|---|---|---|---|
| From the start 3 types | ||||||
 MARS PEOPLE | 5 | 100% | 125 | 50 | 6.67s | 16.67s |
| MARS PEOPLE | 1 | 100% | 125 | 50 | 30.67s | — |
| MARS PEOPLE | 1 | 100% | 125 | 50 | 33.33s | — |
 MARCO | 1 | 100% | 1,500 | 125 | 60s | — |
| MARS PEOPLE | 1 | 100% | 125 | 50 | 80s | — |
| MARS PEOPLE | 1 | 100% | 125 | 50 | 84s | — |
| MARS PEOPLE | Unlimited | 100% | 125 | 50 | 100s | 20–40s |
 Ms. Sign | Unlimited | 100% | 10,000 | 1 | 900s | 900s |
| Once base HP ≤ 90% 3 types | ||||||
| MARS PEOPLE | 3 | 100% | 125 | 50 | Immediately | 20–40s |
| MARCO | 1 | 100% | 1,500 | 125 | Immediately | — |
 ALLEN O'NEIL Boss | 1 | 100% | 6,000 | 600 | Immediately | — |
HP and attack include the magnification.
Clear rewards
If the reward chances add up to more than 100, the rows are rolled in order and each later row shares what is left.
Score rewards
Earned when your battle score reaches that value.